Capital Stock (Details) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Summary Of Changes In Outstanding Common Stock Abstract
Outstanding , beginning of year	93,143	91,673	91,140
Shares issued upon exercise of options	671	677	18
Shares issued under employee stock purchase plan			32
Shares issued for grants of time vested restricted stock	684	773	229
Shares issued upon vesting of performance units		20	254
Outstanding , end of year	94,498	93,143	91,673